crypto/weakcrypto/source/asymmetric/rsadecryptor.cpp
changeset 71 dd83586b62d6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcrypto/source/asymmetric/rsadecryptor.cpp	Fri Jun 11 15:32:35 2010 +0300
@@ -0,0 +1,98 @@
+/*
+* Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the License "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: 
+*
+*/
+
+
+#include <asymmetric.h>
+#include <asymmetrickeys.h>
+#include <bigint.h>
+#include <cryptostrength.h>
+#include <securityerr.h>
+#include <cryptopanic.h>
+#include "rsafunction.h"
+
+/* CRSAPKCS1v15Decryptor */
+
+EXPORT_C CRSAPKCS1v15Decryptor* CRSAPKCS1v15Decryptor::NewL(
+	const CRSAPrivateKey& aKey)
+	{
+	CRSAPKCS1v15Decryptor* self = NewLC(aKey);
+	CleanupStack::Pop(self);
+	return self;
+	}
+
+EXPORT_C CRSAPKCS1v15Decryptor* CRSAPKCS1v15Decryptor::NewLC(
+	const CRSAPrivateKey& aKey)
+	{
+	CRSAPKCS1v15Decryptor* self = new(ELeave) CRSAPKCS1v15Decryptor(aKey);
+	CleanupStack::PushL(self);
+	self->ConstructL();
+	return self;
+	}
+
+TInt CRSAPKCS1v15Decryptor::MaxInputLength(void) const
+	{
+	return iPrivateKey.N().ByteCount();
+	}
+
+TInt CRSAPKCS1v15Decryptor::MaxOutputLength(void) const
+	{
+	return MaxInputLength() - iPadding->MinPaddingLength();
+	}
+
+void CRSAPKCS1v15Decryptor::DecryptL(const TDesC8& aInput, 
+	TDes8& aOutput)const
+	{
+	__ASSERT_DEBUG(aOutput.MaxLength() >= MaxOutputLength(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));
+	__ASSERT_DEBUG(aInput.Length() <= MaxInputLength(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge));
+
+	RInteger input = RInteger::NewL(aInput);
+	CleanupStack::PushL(input);
+
+	RInteger output;
+
+	RSAFunction::DecryptL(iPrivateKey, input, output);
+	CleanupStack::PushL(output);
+
+    TPtrC8 ptr = *(output.BufferLC());
+    iPadding->UnPadL(ptr, aOutput);
+
+    CleanupStack::PopAndDestroy(3, &input); //BufferLC(), output, input
+	}
+
+CRSAPKCS1v15Decryptor::CRSAPKCS1v15Decryptor(const CRSAPrivateKey& aKey)  
+	: iPrivateKey(aKey)
+	{
+	}
+
+void CRSAPKCS1v15Decryptor::ConstructL(void)  
+	{
+	iPadding = CPaddingPKCS1Encryption::NewL(MaxInputLength());
+
+	// Check if MaxInputLength() makes sense, if not the key length must 
+	// be too small
+	if(MaxOutputLength() <= 0)
+		{
+		User::Leave(KErrKeySize);
+		}
+
+	TCrypto::IsAsymmetricWeakEnoughL(iPrivateKey.N().BitCount());
+	}
+
+CRSAPKCS1v15Decryptor::~CRSAPKCS1v15Decryptor(void)  
+	{
+	delete iPadding;
+	}